Ensuring web sites are easy for disabled people to use is no longer an option - it is a legal obligation.

The Royal National Institute of the Blind in Peterborough is warning that anyone running a site faces prosecution if they fail to comply with the law.

Mark Smith is blind and a great fan of the internet. Using voice recognition software he spends hours surfing the net.

Many of the sites he showed me were easy to navigate but not all of them.

When we find a site for a well known tourist attraction in Norfolk there are graphics and pop-up windows.

"It can be quite confusing," he said.

"Often there can be difficulties with graphics on the screen, sometimes there aren't always text labels and sometimes websites are so large you spend some time having to manipulate your speech programme to find the information you need."

Disabled user-friendly tips

All web pages should provide text for every image on screen

Think about the blend of colours you use - it may confuse people who are colour blind

Ensure that moving, blinking and scrolling objects or pages can be paused

The internet has been a godsend for many who are blind or partially-sighted.

Adapted keyboards which allow people to use Braille when they type and special software to enlarge the screen allows access to a world of information.

"It's quite exciting because we can get much more of what we need when we need it, " says Richard West, of the Norfolk and Norwich Association for the Blind.

"But now we've got to learn how to manage all the information that's available."

Under new legislation websites must be easy for disabled people to navigate.

From their offices in Peterborough Julie Howell of the Royal National Institute of the Blind has begun to prosecute organisations whose sites fall short.

"Companies would be really wise to think about this now," she said.

"Opening up a website to more people shouldn't mean stifling creativity - it should bring firms so much more business."

A lot of companies haven't done anything about it yet. You can't avoid this. It is the law and it's enforceable

Peter Ballard, of Foolproof

Some get it right: the BBC website is considered to be one of the best for people with disabilities and on Wednesday Anglia Railways received an award from the RNIB for the excellence of its site.

"A lot of companies haven't done anything about it yet. You can't avoid this. It is the law and it's enforceable," said Peter Ballard, of Foolproof, a company in Norwich which advises companies on web page design.

He said ensuring a site is disabled user-friendly is not as daunting as it sounds.

Fancy graphics and flash technology are fine as long as it can still be read by basic software.

The new legislation applies anyone who runs a website - individuals or companies.

There are signs that some webmasters are beginning to get the message - but many have not and the RNIB is planning to step up its prosecutions until all websites are user-friendly.